How to make a white sauce
Make a smooth, lump-free white sauce (béchamel) from butter, flour and milk – the base for cheese sauce, lasagne, fish pie and cauliflower cheese.
- Time
- 15 minutes
- Difficulty
- Easy
- Cost
- Low cost
- Steps
- 7
- Checked
What you’ll need
- 50g (2oz) butter or spread
- 50g (2oz) plain flour
- 500ml (just under 1 pint) milk
- Salt, pepper and a pinch of nutmeg (optional)
- Small heavy-based saucepan
- Balloon whisk Search Amazon for balloon whisk
- Wooden spoon
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Safety first
- Keep the heat low to medium – milk sauces catch and burn on the bottom quickly.
Step by step
-
Step 1: Warm the milk
Warm the milk gently in a jug in the microwave or in a separate pan. Warm milk blends in more smoothly and is less likely to go lumpy. Don't let it boil over.
Next: step 2 -
Step 2: Make the roux
Melt the butter in a saucepan over a low heat. Stir in the flour to make a paste (a 'roux') and cook it, stirring, for 1–2 minutes. This cooks out the raw flour taste. It should smell slightly biscuity but not brown.
Next: step 3 -
Step 3: Add the milk gradually
Take the pan off the heat. Add a splash of milk and whisk until smooth, then keep adding a little at a time, whisking well each time. Once about half is in, you can add the rest more quickly.
Next: step 4 -
Step 4: Simmer until thick
Return to a low-medium heat and keep stirring or whisking, making sure you get into the corners of the pan, until it bubbles and thickens. Let it simmer gently for a few minutes until it coats the back of a spoon and no longer tastes floury.
Next: step 5 -
Step 6: Short cut: the all-in-one method
Put the butter, flour and completely cold milk in the pan together, then heat gently, whisking all the time, until it boils and thickens. Simmer for 2 minutes, still whisking. The milk must be cold at the start or it will go lumpy.
Next: step 7 -
Step 7: Make it a cheese sauce (optional)
Take the pan off the heat and stir in 50–100g grated mature Cheddar and a teaspoon of mustard until melted. Don't boil it once the cheese is in or it can go stringy.
Tips
- Lumpy sauce? Whisk hard, or push it through a sieve – it'll be fine.
- For a thicker sauce (for lasagne or a pie topping), use less milk; for a pouring sauce, add more.
- Pressing cling film or baking paper onto the surface stops a skin forming if you're making it ahead.
Questions people ask
Can I make it gluten-free?
Yes – cornflour mixed with a little cold milk, then whisked into hot milk, thickens it. The texture is slightly different.
How long does white sauce keep?
Covered in the fridge, up to 2 days. It also freezes well as part of a dish such as lasagne.
Sources
Checked 9 October 2026. We wrote this guide in our own words, using:
- British Dietetic Association: White sauce recipe (bda.uk.com)
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